Bib for preventing leakage from open end mixers



Sept. 15, 1959 L. E. BROBERG BIB FOR PREVENTING LEAKAGE FROM OPEN END MIXE Filed Feb. 11, 1957 lIIlIIIIII/I.

INVENTOR. Leorman E. Became BY ATTORNEY as it discloses a movable chute.

United States Patent BIB FOR PREVENTING LEAKAGE FROM OPEN END MIXERS Leonard E. Broberg, Milwaukee, Wis., assignor to The T. L. Smith Company, Milwaukee, Wis., a corporation of Wisconsin Application February 11, 1957, Serial No. 639,386 3 Claims. or. 259-161 This invention relates to open end transit mixers or agitators and particularly to prevention of spillage from the charging cone.

In reducing the weight of transit mixers the industry has eliminated the rear closing door on the mixers. This has given rise to the problem of eliminating leakage or spillage through the open end of the charging cone which tends to occur due to increased loads or due to surging of the load. The principle object of the present invention is to eliminate this leakage by means of a simple and efficient structure carried by the charging chute. In carrying out this object I provide a rubber bib on the inside of the chute and adapted to project into the cone so gravity and the weight of the concrete press the bib against the cone to effect an efiicient seal. When the chute is swung out for inspection'purposes the bib will flex and break off any adhering concrete, thus providing a self-cleaning action. The bib extends up to the top of the chute to receive the abrading action of the incoming charge and thus relieve the steel of this wear.

Other objects and advantages will be pointed out in, or be apparent from, the specification and claims, as will obvious modifications of the single embodiment shown in the drawings in which:

Figure 1 is a rear view of a transit mixer provided with the present sealing bib;

Figure 2 is a fragmentary side view with parts broken away and parts in section to show the construction of the two piece bib; and

Figure 3 is a fragmentary portion similar to part of Figure 2 but shows a one piece bib.

Referring to the drawings now in detail, truck frame is provided with an inverted U-shaped channel frame member 12 on which brackets 14 are welded for interconnection by inverted angle iron 16. The angle iron is provided with bearing supports 18 which journal shaft 20 on which the chute brackets 22 are journalled for movement about the axis of shaft 20 as the linkage 24, 26 is actuated by hand wheel 28 move the chute hanger arms 30 pivotally connected to chute 32 through laterally projecting arms 34. This type of structure is rather conventional and forms no part of this invention except so far Greater detail of a similar arrangement may be seen in Rockburg Patent No. 2,563,963.

Drum 36 is rotatably mounted in the frame for rotation about an upwardly and rearwardly inclined axis such as customarily employed in the high discharge type of mixer. The rear end of the drum is open and has charging cone 38 mounted therein centrally of blades 40, 42. These blades spiral throughout the length of the drum and serve to work the contents forward when the drum is rotated in the mixing direction and to work the contents to the rear of the drum for discharge when the rotation is reversed.

Chute 32 is provided with a rubber bib 44 secured to the lower end of the chute and extending into the cone as may be seen in Figure 2. In order to prevent material trally of the cone 38. in the cone it will ride up on the rubber bib and hold piling up on the outer edge of the bib and to reduce is secured to the chute by means of bolts 48 at the upper edge and bolts 50 at the lower edge of the lining. The

'bib is secured by another set of bolts 52. With this arrangement the chute is rubber lined and hence is more resistant to abrasion than a steel chute. Rubber bib 44 extending into the cone will act to prevent leakage cen- As material tends to work back the rubber bib tightly against the inner surface of the cone and thus prevent leakage. With this rubber bib the chute can readily be swung to the dotted line position shown in Figure 2 since the bib will merely deflect as it is pulled over the end of the cone. When the chute is swung from the dotted line position back towards the cone it will be necessary to manually help the bib into the cone. This is easy to do since the operator must be at the end of the truck anyhow to operate hand wheel 28.

Figure 3 merely shows an alternative structure wherein a single piece rubber liner and bib 54 is secured in the hopper by means of a single line of bolts 56 at the upper edge of the member. This has the advantage of reducing the number of bolts required to mount the bib and liner and the cost saving may well offset the added cost of the larger piece of rubber necessary to be replaced when only the bib actually would normally be required to be replaced. This change in the construction is a matter of choice but is illustrated here to insure it being within the scope of the invention.

Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1. The combination with a mixer or agitator of the type having an open ended drum rotatably mounted in a fixed frame, the drum having spiral blades on the interior thereof, a charging cone central of the blades adjacent the open end of the drum, of means for preventing spillage from centrally of the cone, comprising a charging chute pivotally mounted in the frame adjacent the open end of the drum, a flexible bib secured to the interior of the chute and projecting into the interior of the charging cone, said bib being of single piece construction and mounted to the chute only at the top opening thereof.

2. The combination with a mixer or agitator of the type having an open ended drum rotatably mounted in a fixed frame, the drum having spiral blades on the interior thereof, a charging cone central of the blades adjacent the open end of the drum, of means for preventing spillage from centrally of the cone comprising a charging chute pivotally mounted on the frame for swinging movement to and from the open drum end, the chute exit being in alignment with the open end of the cone when the chute is in charging position and spaced therefrom, and a flexible bib secured to the inside of the chute and projecting into the cone when the chute is in the charging position to provide communication between the chute and the cone with gravity and the drum contents acting to hold the bib in sealing engagement with the bottom of the cone, said bib extending from the top of the chute and being connected to the top of the chute only whereby the bib acts as a liner for the chute and presents a flexible surface therefor which tends to break off adhering material as it is flexed when the chute moves from the charging position.

' 3. A combination withamixer or agitator of the type 'having an open ended drum pivotally mounted in I a fixed frame, a drum having spiral blades on the inner surface thereof, a charging cone central of the blades adjacent the open end of-the='drum, of rneans for preventing spillage from centrally of the'eone, comprising acharging chute pivo'tally meunte'd in the frame formovement about 1 a ;horizontal axis above-theaopen -end"ofthedrum asub sta'ntially continuous flexibleliner-rnernber for the chute -extendingfrorn the top-portion of the chute downwardly "along theinnersurface of the chute-means securing the liner to the-chute at *a-point-Temotefroni the-lower end of the chute,'=the-1iner between said securing means and 'the' lower endof the chnte being free of attachrnent to the-chute, saidlinerincluding a flexible bib portionprojecting froni the lower =end of the chute' into the interior of the charging cone with the inner extremity of the bib within the conelying a-greater'distance from-the'pivotal References Cited in the file of this patent 'UNITED STATES PATENTS 2,658,603 Fernald Novpll), "1953 2,690,901 -McCorrnack -Oct-..5, 1954 2,750,164 MacKinney June 12, 1956 2,763,474 Smith Sept. 18, 1956 

